How Repressive Regimes Censor the Net, and How U.S. Companies Help How do these “country-wide” firewalls work?
First, a user enters a URL – the address of a Web page – into his or her browser. This URL gets passed to the firewall, which checks to see if it is on a list of Web sites banned by the government. If so, then the firewall refuses to forward the user’s request, and may instead send a message back to the user indicating that access is denied. Firewalls may also be configured to filter Web sites for banned content; to log the IP addresses of users who have requested access to banned sites; and even to snoop on email communications. The consequences of detection by a firewall can be severe – China has jailed dissidents for downloading Internet articles critical of China and executed hackers for committing cyber-theft. Ironically, some of the largest U.S. software companies – firms that have built their fortunes on open access to the Internet – have helped the efforts of China, Iran, and other repressive regimes to build and improve their firewalls. (A law preventing the companies from exp
